1 Answer
1

It doesn't provide any value but for developpement we need this testnet.
So devs are mining on testnet at least to validate their own transactions, but also others. It's a sort of gift to the community as providing code or helping test new versions.

The main benefit for a developper to mine on testnet is to have access to Ether on the testnet. Without testnet Ether you can't create contracts or interact with them.

You can also use faucets that mines testnet Ether and gives you these testnet Ether for free.

I'm not able to resemble this answer to my question. What I'm asking is, how miners get a reward to mine testnet transactions? What's in there for them? If they can get real ether as reward by mining mainnet-transactions then why do they mine testnet transactions?
– PrashantNagawadeFeb 6 '18 at 13:34

3

They did answer your question. You asked why miners mine on testnets, he said because they're developing on the testnet and need it mined, or they're doing it altruistically for the community. Note that most testnets can be mined on cpu because there is very little competition.
– flygoingFeb 6 '18 at 15:42